;
function getCheckCode(elementId)
//生成验证码，将在Id为elementId的HTML元素的innerHTML中写入HTML图片源码{
htmlStr="";
CheckCodeStr=""; //清空原验证码
for (i=0;i<4;i++)
{
num=Math.round(Math.random()*10-0.5);
CheckCodeStr+=num.toString();
filePath=imgFolderPath+imgFileName[num]+fileExt;
htmlStr+="<img border=0 width=@width@ height=@height@ alt=''点击更换一组验证码'' src=''@src@'' onclick=''getCheckCode("@elementid@")'' style=''cursor:hand''>";
htmlStr=htmlStr.replace("@width@",imgWidth);
htmlStr=htmlStr.replace("@height@",imgHeight);
htmlStr=htmlStr.replace("@src@",filePath);
htmlStr=htmlStr.replace("@elementid@",elementId);
}
document.getElementById(elementId).innerHTML=htmlStr;
}
function CheckCodeOK(str)
{
{
return true;
}
else
{
return false;
}
}
test.html
<script language=javascript src=CheckCode.js></script>
<body onload="getCheckCode(''CheckCodeImg'')">
<div id="CheckCodeImg"> <!--验证码图片出现在此处--></div>
<input type=button value="Click Me" onclick="getCheckCode(''CheckCodeImg'')"><br><br>
<input type=text name="CheckCode">
<input type=button value="Check" onclick="if (CheckCodeOK(document.getElementById(''CheckCode'').value)){alert(''OK'');}else {alert(''error'')}">
</body>
摘自 http://www.cnblogs.com/spark_wu/articles/1377402.html